Many things changed when Republican Scott Brown was elected last week to a U.S. Senate seat in Massachusetts that was for decades on the Democratic side of the aisle. The special election buoyed the mood of independent voters, who were reminded again of their electoral clout. It empowered the GOP caucus, ending the Democrats' and President Obama's supermajority.

And in the days that followed it changed the narrative about health care reform, from talk of a near inevitability to the tale of a creature bound for extinction.

That can't be allowed to happen. Congress must start the process of reform with the vehicle most likely to succeed — the Senate bill, paired with a raft of amendments aimed at improving affordability and strengthening elements that "bend the cost curve," as Obama likes to say.

The reason is that in all the political game-changing of the Massachusetts election, one thing didn't change: the need of millions of Americans for affordable health insurance and of the entire nation to come to grips with its skyrocketing health-care costs.

This remains an imperative regardless of anyone's political philosophy about whether access to health care is a basic right or the proper part government should play in assuring it.

The bottom line is that health-care reform is essential to any effort to restore fiscal discipline; without it, the federal deficit will explode even further.

The federal government, in its role as an employer providing health insurance and as the manager of health benefits to the poor and elderly, will be pushed farther and farther into the red ink if the health care system is left uncontrolled.

It's indisputably true that the craven deal-making that's gone on over securing the needed votes for passage has appalled many people. Nebraska Sen. Ben Nelson already has been shamed into yielding his rich exemption for his state from paying added Medicaid bills. That sweetheart deal should be carved out of the bill in the amendments that will be considered in the budget reconciliation process — which doesn't require a supermajority when they cross to the Senate.

And the public uproar over one of the funding mechanisms — the excise tax deferral for union members — is justified. Tagging an assessment to the so-called "Cadillac" plans is an important way to discourage high-end plans and to incentivize more efficient delivery of care. With limited exemptions for those whose jobs require costlier coverage, the tax should be applied more fairly.

Many people would prefer to reform America's health-care system in bits and pieces. But it's impossible to carve out the unpopular sections of the bill, such as the individual mandate, without disabling coverage of those with pre-existing conditions and other popular aspects.

Health reform requires a comprehensive approach. New ways of making care cost-effective will be discovered through the bill's various test programs, while others are jettisoned.

This should be viewed as a long-term process, but one that must begin now. Obama and the Democrats need to do their job and exercise their power for the well-being of the powerless — many of whose voices are not being heard in all the uproar.